Long-term data assessment of chironomid taxa structure and function in the River Thames

Abstract

Discharge of the River Thames is already regulated to prevent flooding and to satisfy demands for water. A flood alleviation channel is under construction, while a pumped‐storage reservoir has been proposed to further regulate discharge for water supply. The aim of this investigation was to assess the suitability of available quantitative macroinvertebrate data for detecting significant change in biological structure and functioning, and substratum composition, following the implementation of these schemes. Pupal exuviae of Chironomidae (non‐biting midges) were collected from eight surveys of the freshwater River Thames from 1977 until 1997. Multivariate and univariate statistics were used to investigate biological variation between surveys, independently of variation between sites. Over 48% of biological variation was explained by the available physical and chemical data. Temporal variation was almost independent of spatial variation. River discharge was the most important environmental variable correlated with chironomid taxa abundances between surveys, particularly in the lower Thames. High concentrations of un‐ionized ammonia occurred during 1977, the effects of this were also greatest in the lower Thames. Indicator taxa have been identified which can be used as a simple monitoring tool to track the effects of varying flow and nitrogen flux between surveys. Proportions of fine sediment‐dwelling chironomids, and their functional feeding types, have not significantly changed at sampling points immediately above or below the proposed reservoir or the imminent confluence with the flood alleviation channel over the 20‐year survey period. These data provide the basis for detecting significant impacts by such schemes if or when they are completed. This knowledge would benefit any future plans to regulate or alleviate river flows. Copyright © 2000 John Wiley & Sons, Ltd.

Chironomids from Southern Alpine Running Waters: Ecology, Biogeography*

“…At present the objective of relating species to environmental factors in alpine inland waters is reached only in part, species groups or genera and not species were generally used in multivariate analysis carried out to emphasise the species response to environment (Ruse & Davison, 2000;Milner et al, 2001); the reason is that species identification is a very laborious task and rarely it is matched by the estimation of species abundances and measurement of environmental variables. CHIRDB allowed the calculation of correlations between environmental variables with species, but the number of samples available was low for many species resulting in high standard deviations (see Tables 2-4).…”

Environmental monitoring using next generation sequencing: rapid identification of macroinvertebrate bioindicator species

“…Chironomids are a speciose group consisting of taxa that vary in their responses to pollution and other environmental characteristics, and they are an important biological indicator group for monitoring, assessing and classifying aquatic environments [45-47]. They are particularly useful as indicators of aquatic pollution in urban areas, because they can dominate benthic urban macroinvertebrate fauna in these areas, representing up > 50% of the aquatic insect species collected in benthic surveys [46,48-50].…”

Environmental factors – spatial and temporal variation of chironomid communities in oceanic island streams (Azores archipelago)

“…Rosenberg and Resh, 1993;Wilson and Ruse, 2005;Raunio et al, 2007b;Raunio et al, 2007a;Heino and Paasivirta, 2008). Further, studies relating environmental variables to the spatial and/or temporal patterns of chironomid distribution are reported from Australia (Hardwick et al, 1995;Dimitriadis and Cranston, 2007), Finland (Raunio et al, 2007b;Heino and Paasivirta, 2008), the United Kingdom (Ruse and Wilson, 1995;Ruse, 2000;Ruse and Davison, 2000), Spain (Calle-Martı´nez and Casas, 2006;Punti et al, 2009) and Japan (Inoue et al, 2005). The association between the environmental variables that determine chironomid community structure is complex, determined by physical, chemical and biological processes that vary both temporally and spatially in the lotic environment.…”